New Research Shows Crude Oil Chemicals Move and Change More Quickly than EPA Standards

03/07/2017

BATON ROUGE –The Environmental Protection Agency, or EPA, lists about 65 chemicals
as “toxic pollutants” under the Clean Water Act, 16 of which are polycyclic aromatic
hydrocarbons, or PAHs. LSU Department of Environmental Sciences doctoral candidate
Parichehr Saranjampour conducted research on a chemical class of PAHs that is not
on the EPA’s list — Dibenzothiophene, or DBT. DBT and its three related chemical compounds
contain sulfur that is found in crude oil. Saranjampour studied how these chemical
compounds move and change over time, which revealed new information that has never
been published before. Her findings differ from the EPA’s information about these
chemical compounds. This new research was published today in the Journal of Environmental Toxicology and Chemistry.

Saranjampour studied two processes that chemicals undergo — evaporation and oxidation,
or what happens when something is exposed to air and light. From lab experiments,
she found that one compound oxidized faster than the currently accepted rate relative
to the four compounds. She also found that another compound evaporates and is released
into the air faster than previously thought, which may have implications on land animals
and humans who come into contact with oil, such as oil rig workers.

“These results indicate that the sulfur containing polycyclic aromatic hydrocarbons
in the crude oil may evaporate very fast after an oil spill on the Gulf of Mexico
surface water,” Saranjampour said. However, her research also shows that these chemicals
may linger in deeper water and convert into other chemicals that may be more water
soluble.

These chemicals are not only found after a crude oil spill, but they can also be found
in water and sediment where crude oil or diesel fuel are present.

“These results call for more research by environmental chemists and toxicologists
to investigate the environmental impacts of these chemicals in water, sediment, air
and on living organisms,” she said.

She is currently investigating the toxicity of these chemical compounds.